US7747400B2ActiveUtilityPatentIndex 91
VA metering in polyphase systems
Est. expiryOct 6, 2026(~0.3 yrs left)· nominal 20-yr term from priority
Inventors:VOISINE JOHN
G01R 21/1331
91
PatentIndex Score
27
Cited by
13
References
12
Claims
Abstract
An arrangement includes an A/D converter and a processing circuit. The A/D converter is configured to generate digital samples of voltage and current waveforms in a polyphase electrical system. The processing circuit is operably coupled to receive the digital samples from the A/D converter. The processing circuit is further configured to combine a value substantially equal to two times the magnitude of the phase A current sample with the phase C current sample to generate a first value, and generate a VA calculation using the first value and at least one other value. The processing circuit is further configured to provide information representative of the VA calculation to one of a group consisting of a display, a communication circuit, and a billing calculation unit.
Claims
exact text as granted — not AI-modified1. An arrangement, comprising:
a) an A/D converter configured to generate digital samples of voltage and current waveforms in a polyphase electrical system;
b) a processing circuit operably coupled to receive the digital samples from the A/D converter, the processing circuit configured to:
i) generate a VA calculation using the following relationship
VA
Source
=
1
3
[
I
→
A
+
2
I
→
C
·
V
→
CB
+
2
I
→
A
+
I
→
C
·
V
→
AB
+
I
→
A
-
I
→
C
·
V
→
AB
-
V
→
CB
]
where {right arrow over (I)} A is the current vector on phase A, {right arrow over (I)} C is the current vector on phase C, {right arrow over (V)} CB is the voltage vector across phase C and phase B, and {right arrow over (V)} AB is the voltage vector across phase A and phase B;
ii) provide information representative of the VA calculation to one of a group consisting of a display, a communication circuit, and a billing calculation unit.
2. The arrangement of claim 1 , wherein the processing circuit is further configured to generate a first value representative of {right arrow over (I)} A +2{right arrow over (I)} C at least in part by combining a value substantially equal to two times the magnitude of a phase C current sample with a phase A current sample.
3. The arrangement of claim 2 , wherein the processing circuit is further configured to generate a second value representative of {right arrow over (V)} CB based at least in part on phase C voltage samples.
4. The arrangement of claim 3 , wherein the processing circuit is further configured to generate a value representative of a product of the first value and the second value.
5. The arrangement of claim 1 , wherein the processing circuit is further configured to generate a first value representative of 2{right arrow over (I)} A +{right arrow over (I)} C by combining two phase A current samples with a phase C current sample.
6. The arrangement of claim 1 , further comprising the display, and wherein the display is configured to display the information representative of the VA calculation.
7. An arrangement, comprising:
a) an A/D converter configured to generate digital samples of voltage and current waveforms in a polyphase electrical system;
b) a processing circuit operably coupled to receive the digital samples from the A/D converter, the processing circuit configured to:
i) generate a first value at least in part by combining a value substantially equal to two times the magnitude of a phase C current sample with a phase A current sample;
ii) generate a VA calculation using the first value and at least one other value;
iii) provide information representative of the VA calculation to one of a group consisting of a display, a communication circuit, and a billing calculation unit.
8. The arrangement of claim 7 , wherein the processing circuit is further configured to combine two phase A current samples with the phase C current sample to generate one of the at least one other values.
9. The arrangement of claim 7 , wherein the processing circuit is further configured to generate a second value representative of a voltage difference between phase C and phase B based at least in part on phase C voltage samples.
10. The arrangement of claim 9 , wherein the processing circuit is further configured to generate a value representative of a product of the first value and the second value.
11. The arrangement of claim 7 , further comprising the display, and wherein the display is configured to display the information representative of the VA calculation.
12. The arrangement of claim 7 , further comprising the communication circuit.Cited by (0)
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